A “Hail Mary type of concept” that “will exacerbate erosion and slope failure and will eventually fail.” That’s a description of the plan for storing mining waste at the proposed PolyMet mine in northeast Minnesota.

These descriptions come not from a mining opponent, but from a mining consultant hired by the Minnesota Department of Natural Resources (DNR) to evaluate the PolyMet proposal. These comments are only one of many troubling indicators that the current permit for mining is deeply flawed.

In Minnesota, the PolyMet mining proposal has created significant division between advocates for the mine and advocates for the environment. Gov. Mark Dayton has attempted to bridge that divide, saying that we can have mining and protect the environment, as long as we use best practices for mining and provide “safeguards” to prevent damage. Jon Cherry, the CEO of PolyMet, has committed to “meet or exceed regulatory standards and industry best practices.”

Those commitments outline what could be a good compromise — one that could bring both sides of this contentious issue together: Allow the PolyMet mine to proceed, but only if it uses best practices. Unfortunately, the draft permit, which appears to be nearing DNR approval, fails this test and lacks the safeguards called for by the governor.

Let’s not delude ourselves into believing that Minnesota has strong environmental standards for mines. The DNR mining consultant, Don Sutton of Spectrum Engineering, said: “I am surprised that the Minnesota Statutes allow a temporary [tailings] impoundment structure to be permitted permanently. This wouldn’t be allowed in other jurisdictions.” [Emphasis added.]

Sutton also brought up concerns about the long-term instability of the waste rock “tailings” pond banks from erosion, and calls the risk of long-term failure of the dam an “almost certainty.” He explained that because of this erosion, “at some point the entire mass will unravel.”

Why does this matter? A similar mining operation in British Columbia had a catastrophic dam failure in 2014 that released a toxic slurry of waste rock in one of the worst environmental disasters in Canadian history.

After that Mount Polley mine disaster in British Columbia, a comprehensive review called for dry storage of mine tailings as a best practice, along with a requirement for an independent review to monitor the projects. Using these best practices would prevent the catastrophic harm caused by a dam collapse.

The DNR mining consultant wrote that “if the tailings were placed in a dry, compacted state, I wouldn’t be so concerned.” When a good solution like this exists, why doesn’t the PolyMet plan look at dry storage of the waste?

Mining consultant Sutton explains that “PolyMet is proposing to build the tailings disposal system that has the lowest initial cost, but has more long-term risks than other tailings disposal methods.” He says that the state should “consider the consequences of a failure and estimate the cost of cleaning up the failure, and then add the cost of operating the repaired facility forever.”

PolyMet’s unwillingness to use best practices might come from its biggest investor — Glencore, the multinational mining company that will receive the first profits from the mine. The chairman of Glencore, Tony Hayward, was the chief executive at BP who was widely condemned for his poor management of the massive Deepwater Horizon oil spill in the Gulf of Mexico. Does Minnesota want Hayward’s current company to make huge profits at the expense of Minnesota’s environment?

The DNR recognizes that it will cost more than $1 billion to clean up the mess from the PolyMet proposal if nothing goes wrong — far more if the dam collapses or anything else fails. Both the DNR and PolyMet claim that PolyMet will be responsible for the costs. Dayton said that he wants a “rock-solid” requirement that PolyMet set aside enough money to pay the cleanup costs.

The DNR hired financial experts and mining engineers to advise the state on how to protect taxpayers from these costs, but the DNR draft permit ignores some of the most important recommendations of their consultants. For that estimated billion-dollar-plus cleanup bill, PolyMet would be required to set aside less than $30 million in the first 10 years of the mine — the most profitable 10 years of copper extraction. Despite the DNR financial experts’ concern that they will not be able to get surety bonds and letters of credit to cover the cleanup costs, the DNR draft permit relies on this risky scheme. This is not the “rock-solid” financial guarantee that the governor called for.

If the DNR permit required PolyMet to put its money on the table to guarantee that taxpayers aren’t on the hook, PolyMet might follow best practices and use the dry tailings storage. It would cost more initially but would protect against environmental harm and avoid the need for many centuries of water treatment.

PolyMet recognizes that once it begins mining, the state will have no leverage to force it to pay for the mine cleanup. Its financial model works if it doesn’t really have to fund the cleanup costs that it promises to pay for.

Decades from now, taxpayers will likely foot the bill to clean up the mess. People will look back to 2018, wondering why state leaders agreed to a mine permit with such flimsy financial requirements.

Dayton’s statements about going ahead with the mining but doing it right — using best practices — accurately reflect Minnesota’s needs. Unfortunately, the draft permit does not require best practices.

Mining can be done properly, but the draft permit falls short. The state must address the concerns raised by the mine engineers and financial consultants the DNR hired. At that point the DNR can draft a reasonable permit that enables the PolyMet mine to proceed, but only if it uses best practices. That would be an excellent compromise. And it would fulfill Gov. Dayton’s commitment to Minnesota.

John Marty, DFL-Roseville, is a member of the Minnesota Senate and is former chairman of the Senate Environment and Energy Committee.